Fuel-injection mechanism and method



Feb. 3, 1931. c. P. CLARK ET Al. 1,791,443

FUEL INJECTION MECHANISM AND METHOD Original Filed April 25. 19272Sheets-Sheet 1 Feb. 3, 1931. c. P. CLARK ET AL 1,791,443

FUEL INJECTION MECHANISM AND METHOD Original Filed April 25, 19 7 2Sheets-Sheet 2 Patented Feb. 33, 193i UNETE TATES CHARLES PAUL CLARK,01F OLEAN, AND CARL YORK, ASSIGNORS TO CLARK BROTHEBfi YORK A.BQTORNNSON, F WELLSVTLLE, NEW COMPANY, A COORATION OF NEW FUEL-INJECTIONMECHANISM AND METHOD Original application filed. April 25, 1927, SerialNo. 186,329. Patent No. 1,893,546, dated November er,

' 1928. Divided and this. application filed This invention relates to animprovement in fuel injection mechanism and method, especially designedfor an internal combustion engine, and is a division of our formerapplication Serial No. 186,329, filed April 25, 1927, now Patent No.1,693,546, November An object of the invention is to arrange the fuelinlet in alignment with and in the direction of the exhaust ports of thecylinder, so as to introduce the fuel at one side of the outer end ofthe cylinder andin the general direction of the exhaust port to insureof a thorough mixing of the fuel with the air used in scavenging thecylinder. Compressed air only is used in the scavenging operation,andnear the completion thereof the fuel injection valve is openeddirectly in the cylinder to admit the fuel into the path of the air soas to have a thorough mixing thereof prior to the explosion.

In the usual type of two cycle gas engine, the charge (air and gasmixture) is precondpressed to a few pounds above atmospheric pressure ina separatelcompression chamber. The expanded gases exhaust throughcylinder ports uncovered by the piston near the end of the expansionstrokes. When their pressure has fallen nearly to atmospheric pressure,the precompressed charge enters through ports also uncovered by thepiston and sweeps out the burned charge. "The process of exhausting theburned gases, scavenging of the cylinder and admitting the fresh chargetakes place through a period representing about one-fifth of the lengthof the expansion stroke and through an equal length at the first part ofthe compression stroke. During this process of scavenging, a largepercentage of the fresh charge is lost through the exhaust ports whichare full open at the height of the scavenging period and remain openafter this period is over, allowing a large percentage of the freshcharge to escape into the exhaust line from the engine.

The spaceoccupiedby the gaseous fuel in the fresh charge is considerableand it compared with the cylinder volume, the ratio of this gas to airrepresents a proportionate amount in loss of engine output March 15,1928. Serial Kilo. 262,009.

partly in side injection valve.

As illustrated in Fig. 1, the fuel is drawn from any suitable source ofsupply, through a pipe 1 to the pump and compressor 2, which is operatedby means of a suitable motor 3,

and the fuel is forced from the compressor 2 through a pipe 4 to asupply tank 5.

A reducing valve-6 is interposed in the pipe 7 which extends from thesupply tank 5 to the cylinder 8 for supplying the fuel thereto. Thisreducing valve 6 may be set to deliver the gaseous fuel at any suitablepressure desired, which will insure the most economical operation of theengine.

The internal combustion engine to which this fuel injection mechanismmay be applied may be of any suitable form and construction and isdesignated generally by the numeral 9. The main drive shaft 10 of theengine 9 has the fly-wheels 11 fixed thereon, which are driven from thepiston 12 operated in the cylinder 8. The manner. of this drive isconventional and, being well understood, is not set forth in detail.

A lay shaft 13 is connected in any suitable manner with the driveshaft-1O to be rotated therefrom. The outer end of the lay shaft 13 ismounted in a bearing 14 supported by a suitable bracket 15 carried bythe engine housing. This bracket is provided with a cover 16. The layshaft 13has a cam 17 fixed thereon, as clearly shown in Fig. 2, inposition to actuate a lever 19 pivoted to a bracket or arm carried bythe supporting bracket 15. The outer end of the lever 19 supports a pushrod 21, the upper end of which engages a horizontal lever 22 carried bya shaft 23 mounted in bearings 24: in the cover 16.

The shaft 23 also carries a vertical arm 25 which is connected withasecondary push rod 26,'as shown in Fig. 2. The outer end of the pushrod 26 is operatively connected with one end of the valve lever 2?pivoted as at 28 in brackets 29 carried by valve casing 30. As shown inFig. 3, the opposite end of the lever 2-7 is connected with a placed inthe center of the end cover of the cylinder 8, and said sparlr plug issuitably connected with a magneto 37. The valve casing 30 is secured tothe end of the cylinder 8 on one side of the sparlr plug 36. The

.gaseous fuel is discharged from the casing 30 about the valve 32 whenunseated in a direction at an angle to the center axis of the cylinder8, and in the general direction of the exhaust ports 38 arranged in oneside of the cylinder in position to be covered and uncovered by thepiston 12.

Arranged on the opposite side of the cylinder from the exhaust ports 38is an air port 39 through which compressed air is sup-.

plied. to the cylinder for the scavenging oporation. This port islikewise adapted to be covered by the piston, and on the side next tothe port39 the piston 12 is provided with the shoulder 40 in position todirect the compressed air in an upward direction toward.

the fuel injection valve 32- It will be noted that the fuel injectionvalve is on the same side of the cylinder with the compressed air inletport, althou h the fuel valve is in the end of the cylin er but at oneside of said end, and the exhaust ports areal-ranged on the oppositeside of the cylinder.

In the operation 'of the machine, the gas or fuel is pumped into thetank 5 by the compressor 2 from where it passes through the reducingvalve 6 and the pipe. 7, into the cylinder 8.

The rotation of the lay shaft 13 from the drive shaft 10 causes arotation of the cam 17,

-which rocks the lever 19, causing aperiodical lon 'tu'dinal movement ofthe push rod 21 and y reason of the bell-crank levers 22 and 25 mhuntedon the shaft 23 causes a similar longitudinal movement ofthe push rod26, which, in .turn, rocks the lever 27 and periodically moves the valvestem 31 inward against "the tension of the s ring 35 to unseat the valve32 for admitting a supply of fuel into the cylinder 8. The position ofthe injector valve 32 is most advantageous and,

avenues fresh air is precompressed and admitted tothe cylinder throughthe port 39 during the hack stroke of the piston and a portion of thereturn stroke, which uncovers this port,

allowing the air to pass in and through the cylinder to force out theexhaust gases on the return strolre of the piston.

When the ports are partly closed, as shown in Fig. 2, the valve 32 ismoved from its seat 33 to allow the injection of gaseous fuel into thecylinder. The shoulder 4L0 directs the air toward the injection valve 32and during this forward motion this compressed air picks up the geseousfuel which had just been admitted, resulting in an intimate mixture ofgas and air. The motion of the mixture, when reaching the bottom of thecylinder, is de flected outward again, resulting in a revolving mass andinsuring of complete mixture of the fuel and air. The fuel injection iscompleted when the working piston has traveled about forty-five per centof the compression stroke, at whlch point the pressure in the cylinderand in the injection valve are about balanced.

In this manner, compressed air only is used for the scavenging operationand the fuel is admitted directly into the cylinder for min ture withthe air at the close of the scavenging operation, which insures of athorough v mixing of air and gaseous fuel. The relation of the injectionvalve, the compressed air port 39, shoulder 40 and exhaust ports 38insures of this thorough mixing operation.

We claim Y 1. A method of introducing fuel into the cylinder of aninternal combustion engine including introducing the fuel at one side ofthe outer end of the cylinder and in the ge eral direction of theexhaust port thereof.

3. A method of introducing fuel into the cylinder of an internalcombustion engine including the introduction of the fuel into one sideof the outer end of the cylinder on substantially the opposite side fromthe exhaust' port and directing said charge in the general direction ofthe exhaust port.-

3. In a device of the character described, the combination of aninternal combustion engine cylinder, having exhaust and scavenging portstherein the exhaust port being located on one side only thereof, andmeans located in the end of the cylinder on the op posite sides thereoffor directing a charge of fuel in the general direction of the exhaustport.

4-. In a device of the character described,

' memes 7 piston operating in said cylinder for controlling said portsand means locatedin the end of the cylinder for directing a charge offuel into the cylinder in the general direction of the exhaust port.

5. Ina device of the character described, the combination of aninternal. combustion engine'cylinder, having exhaust and scavengingports in opposite sides only thereof, a piston operating in saidcylinder for controlling said ports, and valve mechanism located in theend of the cylinder at one side of the center thereof, and inclinedrelatiye to the center axis of the cylinder" or directing a charge offuel into the cylinder in the general direction of the exhaust por 6. Inan internal combustion engine, a cylinder having exhaust andscavengingports in the sides thereof, a piston operatively mounted insaid cylinder and controlling said exhaust and scavenging ports, and avalve mechanism connected with the outer endaof the cylinder and beingdisposed on'the same side of the cylinder as the scavenging port, saidvalve mechanism directing a' charge of fuel directly into the cylinderin the general direction of the exhaust port.

7. In an internal combustion engine, a cyl-' inder having exhaust andscavenging ports disposed approximately on opposite sides thereof, apiston operatively mounted in said cylinder, said piston having ashoulder formed thereonon the side of the scaveng: mg port and to directthe scavenging air tothe cylinder and approximately in the di rection ofthe exhaust port to discharge a charge of fuel toward the exhaust port,and a piston operatively mounted in the cyhnoler and having means todirect scavenging air toward the fuel intake valve mechanism.

In testimony whereof We afix our signatures.

CHARLES PAUL CLARK. CARL A. BJORNNSON ward the outer end of thecylinder, and valve mechanism connected with the outer end of thecylinder and being disposed on the same side of the cylinder as thescavenging ports, said valve mechanism directing a charge of fueldirectly into the cylinder at an angle to the axis of the cylinder andin the general direction of the exhaust port. V 8. In an internalcombustion engine, a cylinder having one or more exhaust ports disposedon a side only thereof, and valve mechanism connected with the outer endof the cylinder and disposed on'the opposite side thereof from theexhaust port, said valve mechanism being arranged at an angle to theaxis of the cylinder and directing a charge of" fuel approximately inthe direction of the exhaust port.

9. In an internal combusi on engine, a cylinder having one or moreexhaust ports disposed in one side only thereof, a scavenging portdisposed on the opposite side of the cylinder from the exhaust port,fuel intake valve mechanism connected with the outer end of the cylinderand disposed on the opposite side thereof from the exhaust port,

said valve mechanism having the axis thereof extending at anacute 1, tothe of

